Described herein is a photoelectric conversion element and a wavelength sensor.
There is known to be a photoelectric conversion element disclosed in JP 2009-71147A (Patent Document 1). The photoelectric conversion element disclosed in Patent Document 1 is a plasmon resonance photoelectric conversion element that uses plasmon resonance to convert light energy into electrical energy. As disclosed in paragraph 0031 of Patent Document 1, with this photoelectric conversion element, electrons on a metal thin film surface that have been excited due to light absorption caused by plasmon resonance move to a semiconductor thin film, and thereby electrical energy is generated.
Incidentally, as is evident from FIG. 7 of Patent Document 1, the strength of light absorption (absorbance) caused by plasmon resonance is wavelength-dependent, and as a result, the photoelectric conversion efficiency is also wavelength-dependent following a similar trend. However, the wavelength dependence of the photoelectric conversion efficiency is merely a phenomenon in which the degree of efficiency of the energy conversion changes according to the wavelength of the light to be converted, which is light to be subjected to photoelectric conversion, and the movement direction of the electrons in the photoelectric conversion element is basically the same direction regardless of the wavelength of the light to be converted. For this reason, for example, if consideration is given to using the wavelength dependence of an output signal of the photoelectric conversion element, the difference between the output signals for different wavelengths is not necessarily clear. However, no special recognition of this point is made in Patent Document 1.